Weren't they suppose to be sisters at first in the comics, or was it always a aunt/niece relationship?

Well, yes.

EDIT: That is to say, when she first appeared, Peggy was Sharon's older sister. As the decades went on, it became less and less likely for their parents to have had two daughters with such a massive age gap, so they were made to aunt and niece, and one suspects it'll be great-aunt sometime soon.

im voting for Sharon. it would bring up a romantic twist because Sharon will remind Cap of Peggy so much that it could possibly drive Sharon crazy to the point where she wont want to love him anymore. could get pretty dramatic.

I know Emily Blunt is under Marvel's eye. She'd make a good Sharon IMO.

I'm not sure why but I get the impression Marvel is aiming for a younger actress for Carter..considering names like MEW, JBF, Emilia Clarke, Anna Kendrick and Felicity Jones have been linked..plus they might end up killing off Carter... Blunt seems more like a franchise sort of actress hence why they wanted her for Widow and is rumored for Ms. Marvel.. characters that are more than likely to get their own films

Again, give those actress mentions a grain of salt, even MEW herself says she has no idea where the Sharon Carter rumor came from.

And there's been nothing to insinuate that Carter would be killed off. Anywhere. Now you're just adding fluff.

Carter isn't exactly a character that stands out in the greater Marvel universe.. she's fair game to get an axe like Coulson was.. I did say "might" because we never know for sure until the film is released..you are right it's not for sure Sharon but who else could it be? Jessica Drew and a very limited amount of female characters come to mind..

I trust Latino Review and Deadline..the latter is one of the more respected film industry trade news outlets.. so when they mention actresses it's not some off-colar comment from an interview or rumors/speculation they have direct studio/agency sources.. Mary Elizabeth Winstead denied LR's casting story since she couldn't confirm it even happened because of the agreements these actors sign..LR has been on the money with a majority of their insider stories, they've even been sued by Marvel over releasing movie plot points and broke a ton of stories like these previously only to be confirmed months later.. the site has a very strong record with their stories..

We all but know the female role is Sharon Carter; What I said is that MEW had no idea where her rumor of being involved in the movie came from aka her rumor being bull.

the "rumor" came straight from Latino Review.. my impression was she was playing dumb because most people who talk about a pending role to press tend not to get it..the only thing that I find odd about their story is that they're looking for an actress with a UK accent..MEW can't do one as convincingly as the British actresses mentioned

I hope you're right, but they're in pre-production. Evans, Mackie and Grillo have started training, locations are/have been scouted, costumes are being fit, etc.

It seems unlikely that JBF would have time to wrap up Winter's Tale and then prepare for the role adequately.

Winter's Tale seems like it will be done in time for her training to start-up...however, Peggy really only had scenes with guns..I'm unsure if Sharon will have training on the level of Johansson's Black Widow.. the gents thave to bulk-up which takes a long time